The present invention relates to a process for removing hair and wool from entire animal pelt.
This method is a radical departure from methods currently used for removing wool or hair from animal pelts. By way of reference, two of the more conventional current methods of removing hair or wool from the pelt (dewoolling or peeling) are described below:
(a) Sodium sulphide and calcium hydroxide method.
The fleshy side of the skin is painted or impregnated with sodium sulphide either by hand or by an appropriate mechanical means. The sodium sulphide penetrates from the flesh to the root of the wool or hair and destroys it. A delay necessarily occurs between the time of application of the sodium sulphide and the time the union between the skin and the wool or hair is destroyed. Once the hair or wool has been removed the skin deteriorates rapidly and washing and neutralizing operations must be carried out as quickly as possible.
The wool or hair is effected in the same manner by the sodium sulphide and should be rinsed immediately to avoid deterioration and putrefaction. The washing process must be carried out particularly effectively to ensure that the residue of the sodium sulphide is diluted and neutralized as well as to rinse away the dirt in the wool or the hair.
It should be kept in mind that the most important side of the skin is the grain or natural pore surface from which the hair or wool is extracted and great care should be taken during all treatment processes.
The epidermis, which is a fine protective layer covering the grain of the skin, is seriously effected by chemicals present in the sodium sulphide bath. For this reason, great care must be taken in the preparation of the solution used to remove the wool or hair, as excessively concentrated solution may cause irreparable damage to the grain side of the skin. Such blemishes are known in the trade as "low grain" and may consist of stains, unnatural swelling or even rupture of the structure of the epidermis. It is clear that this process carries with it considerable disadvantages.
(b) Putrefaction method
The pelt is placed in a temperature and humidity-controlled room until a definite opening or enlargement of the wool or hair follicle is noted. At this stage, the hair or wool may be pulled away from the skin either manually or by using appropriate mechanical methods. This process is normally employed by wool traders and not by Tanners and consequently the skin receives deleterious treatment as it is allowed to reach a semi-putrid state due to the heat and the humidity. Skins which have been subjected to this process are generally of inferior quality. This process, however, does have the advantage that the wool or hair remains unaffected by chemicals unlike the previously described process.